As a meter illumination device of this type, there is a known type having a configuration in which a meter body having a drive shaft provided so as to project therefrom is mounted on a circuit board, an indicating needle which is lit upon receipt of illuminating light from the side of a center of rotation is mounted at a distal end of the drive shaft, a display panel (dial panel) having translucent markings such as calibration markings or characters along an orbit of rotation of the indicating needle is mounted on the back side of the indicating needle, and the markings and the indicating needles of the display panel are lit by a luminous source arranged on the back side of the display panel.
As the meter illumination device of this type, a light guide is disposed on the back side of a display panel, so that light from the luminous source is guided into the light guide and guided to an exit portion of the light guide, and then guided from the exit portion to a proximal portion of the indicating needle, which is a center of rotation of the indicating needle, thereby displaying an indicating portion of the indicating needle with light emission, or the markings of the display panel are lit therethrough via the light guide provided on the back side of the display panel. In such a meter device, since the meter body is arranged on the back side of the circuit board, the light guide formed into a flat panel shape can be arranged between the luminous source and the display panel, and hence a substantially uniform and bright illuminating effect is obtained while reducing the thickness of the lighting device structure as a whole.
However, since the light guide is required, there is a problem in that the cost of the components and the weight of the entire device are increased, and the illuminating structure becomes complicated.
Accordingly, in Patent Document 1, for example, a configuration in which light reflected by irradiating a reflecting surface with radiated light beams from luminous sources arranged so as to surround the rotational center of an indicating needle via a reflecting wall which constitutes part of a meter case is caused to illuminate markings provided on a display panel, or light is guided toward a proximal portion of the indicating needle by a tubular portion provided integrally with a meter case to light up an indicating portion of the indicating needle without using a light guide or the like is known.
Therefore, by providing a reflecting wall or a reflecting surface on the meter case, an illumination device of the meter case can advantageously be made up of relatively simple constituent means without adding components such as individual light guides, which is effective for cost reduction.